Performance enhancement of recycled aggregate concrete - An experimental study

Extensive studies have been performed on the mechanical and durability properties of the concrete prepared with recycled coarse aggregates (RCA), however, only the modest consideration has been given to the studies on the behavior of RAC prepared by different mixing approach techniques. This study presented the mechanical properties of the recycled aggregate concrete (RAC) with different percentages of RCA prepared by normal mixing approach (NMA), two-stage mixing approach (TSMA) and sand enveloped mixing approach (SEMA) techniques. The manufactured concrete mixtures were tested for compression, tension, flexure and elastic modulus at 7, 28 and 90 days. The results indicated that the mechanical properties of the RAC (with 100% of RCA) prepared through TSMA and SEMA were improved by 9.36 and 12.14% at 28 days. Prolonged, prolonged curing to TSMA and SEMA mixtures improved the mechanical properties of the RAC that was nearly equal to normal aggregate concrete (NAC) prepared by NMA.